Circuit interrupter



d 7 Sme, mm R.: Ona 2 Z mad. 6 M VFW T 7 N. T 2 IL. A N h# HJ L HW A R T E 5 E n M U 1 S R n N mm 2 H .w u. T y f U T J M u m .4 fm* LMU.. MZ 4 4 ,M i Mu.. F ..1 M o. Z /ff//f/ /f/ H 8 3 f/ /f/f/ f s l l/ 6 u Jan. 6, 1953 Patented Jan. 6, 1953 UNITED'. STATES PATENT OFFICE CIRCUIT. .INTERRUPTER Application July'Z, 1945, Serial No. 602,876

(Cl. ZOO- 89) 22 Claims. 1

This invention relatesgenerally to. automatic reclosing electric circuit. interrupters, andespecially to novelmeans for causing opening of the interrupter at diierent times after the occurrence of a predetermined circuit condition on predetermined circuit opening operations in any sequence of closely succeeding circuit opening operations.

In our copending application A Serial No. 537,760,- led. May 27, 1944, now Patent No. 2,549,336, dated April 17; 1951, on Circuit Interrupters, which is assignedto the same assignee asthis invention, there is disclosed an automatic reclosing circuit interrupter having fluid dashpot meansior delaying circuit closing operations and certain circuitvopening operations in any sequence of closelysuccessiveoperations of the interrupter. This invention relates to an interrupter of the same general type disclosed in our copending application, and especially to certain modifications in the control of means for delayingA circuit opening and closing operations.

OneV object -of this invention is to provide in an automatic reclosing circuit interrupter, novel meansl for'v delaying at least one predeterminedcircuit, opening operation in: any sequence of closely succeeding lcircuit opening operations, but

which' is ineiective to delayanother .predetermined circuit opening :operation many. such sequence of operations.

Another object of this inventionv is to provide in an automatic reclosing circuit interrupter, a single time .delay means controlled in a novel manner-for-delaying each'circuit closing operation of the'interrupter, and for .delaying at least one predetermined circuit opening operation in any sequence of closely successive circuit opening operations, but which is rendered ineffective to delay-another predetermined circuit opening operation in any such sequence of operations.

A more specific object of this invention is to provide in an automatic reclosing Acircuit interrupter having time -delay means actuated each time the interrupter 'operates-to open the circuit for delaying openingA of the circuit by said interrupter, with means permitting relatively freeV operation of at least a part of said time delay means on at least one predetermined circuit interrupting operation in any sequence of closely successive circuit interrupting operation, and causing more restrained operation of said time delay means on at least another predetermined circuit opening operation in any such sequence.

Another object of this invention is to provide in an automatic reclosing circuit interrupter having a fluid dashpot adapted to be actuated eachv time the interrupter operates to open the circuit, novel means for varying the delaying eiect of said dashpot.

Still another object of this invention is to provide in an automatic reclosing circuit interrupter,

novel means for predetermining .the particular circuit opening operation or operations in any series of closely successive operations which are to be delayed relative to another opening-operation in such a series.

Another object of this invention is Ito provide in an automatic reclosing circuit interrupter having means for causing relatively fast and slow circuit interrupting operations thereof in a predetermined sequence of a plurality of closely successive circuit interrupting operations, novel selective means for causing all circuit interrupting f operations of the interrupter to occur at the same rate.

These and other objects of this invention will become more apparent upon consideration of the following description of preferred embodiments- As previously stated, this invention is capablel of application to automatic reclosing circuit interrupters generally, and is illustrated herein as being embodied in an interrupter similar to that shown in the aforementioned copending application, certain features of which are more clearly disclosed in J. M. Wallace Patent 2,333,604, on a Circuit Interrupter, issued November 2, 194:3,vtol

the same assignee as this invention. This particular type of interrupter is adapted to be housed y in a substantially cylindrical casing 2 of insulating material, such for example as porcelain or the like, with the casing adapted to be supported at an intermediate portion as by a supporting bracket 4. As viewed in Fig. 1, the lower end of 'casing 2 is closed by a closure disk 5 cemented or otherwise secured against a shoulder provided in the lower end of casing v2, at a distance above the lower end of the casing, so as to provide a skirt 1 for concealing the lower terminalY connection. Bottom closure disk 5 for casing 2 is provided with a central aperture for receiving a terminal bolt 6 having an enlarged head 8 adapted to be seated against the closure disk on a compressible gasket |0, of rubber or similar compressible sealing material. Terminal bolt G is provided with a nut |2 for securing it in place, and for securing a terminal fixture I4 thereto.

Adjacent the upper end of casing 2 there is provided a channeled supporting ring i6 secured to the casing in any desired manner, such for example as by cast metal I8 interlocking with the channeled ring and with peripheral grooves provided about the upper end of casing 2. A cover casting 20 for the upper end of casing 2 is adapted to be secured on the upper end of casing 2 by any desired means, such as by bolts or the like (not shown) cooperating with the cover casting 20 and supporting ring I6. Cover casting 20 is provided with a hollow chamber 22 opening to the interior of casing 2, and with an integral hood 24, for a purpose to be described.

Within chamber 22 of the cover casting there is provided a supporting shaft 26 extending transversely thereof with its ends mounted in opposite sides of the chamber, for pivotally supporting an inverted U-shaped spring support 28. Support 28 is provided with apertures in the leg portions thereof for pivotal mounting on shaft 26, and one leg is pivotally connected with one end of a rod 30, with the other end of the rod being slidable in the aperture of a lug 32 provided integral with cover casting 20. A spring supporting nange or disk 34 is secured on rod 30, toform the reaction point for one end of a coiled compression lockout spring 36, the other end of which reacts against a washer seated on lug 32. It will be observed that spring 36 acts to bias support 28 in a counterclockwise direction about shaft 26, but such movement of support 28 is normally prevented by toggle means comprising a toggle lever 38 pivotally connected to one leg of support 28 at one end, and pivoted at its other end to another toggle lever 40 which, in turn, is pivotally mounted on cover casting 20, as at 42. Toggle lever 40 is provided with an integral handle extension 44 having a hookeye 46 in the outer end thereof and adapted, in its normal position shown in Fig. l, to engage a stop bolt 48 provided beneath hood 24 which may be secured in an adjusted position by means of a lock nut 50. It will be noted that in the normal position of the parts illustrated in Fig. 1, toggle levers 38 and 40 are held at an overcenter position by spring 36, with handle 44 defining this overcenter position by its engagement with stop bolt 48. Moreover, in this position of the parts, handle 44 is located substantially entirely beneath hood 24.

A contact actuating lever 52 is also pivotally mounted on shaft 26 within cover chamber 22 and has its inner end 54 extended so as to be engaged by one end of a spring 55 coiled about shaft 26, with the other end of this spring reacting against the bight portion of support 28. Inasmuch as support 28 is normally held against movement by the toggle levers described above, it is apparent that spring 55 acts to normally bias actuating lever 52 in a clockwise direction may be of any desired insulating material, such as fiber or a molded insulating material. The lower end of contact rod 58 is provided with a contact head 64 for engagement with a stationary contact 66 secured in the interrupter chamber. In general, the interrupter chamber 52 comprises a tubular member 63 of insulating material such as liber or the like, with a top cap 68 apertured -to slidably receive the contact rod and its sleeve 60, and a bottom cap l0 is provided to which stationary contact 66 is secured. Bottom cap 'l0 of the interrupter chamber is electrically connected with terminal bolt 6 by means of a coiled compression spring I2 of a resilient electrical conducting material, which reacts between the head 8 of terminal bolt 6, and bottom cap I0 of the interrupter chamber.

Contact rod 58 also passes downwardly through apertures provided in the legs of a generally U-shaped frame 14 which supports an annular solenoid coil 16. An apertured collar 15 is held against an interior shoulder provided about the aperture in the top leg of supporting frame 'I4 by a cylindrical dashpot sleeve preferably of a molded insulating material, and this, in turn, is held in place by engagement with the lower end of sleeve '|1 of the top plate 18 of a generally rectangular shaped supporting frame, which is secured to the lower leg of solenoid supporting frame 14 by means of bolts 80. Top supporting plate 18 may be integral with spaced side plates 82, and these, in turn, may be integral with top cap 68 of the interrupter chamber. Solenoid supporting frame 14 is thus secured to interrupter chamber 62, and these parts are all adapted to be supported from cover casting 20 by means of supports 84 connected between the top leg of frame `|4 and the cover casting, so that all the parts may be inserted or removed from casing 2 as a unit with cover casting 20.

Contact rod 58 is provided with an actuating tube 86 thereon within solenoid coil 16, and the upper end of this tube has a flanged collar 88 adapted to be seated on top of collar 15 and to engage a shoulder 90 provided on the contact rod, for a purpose to be described. A substantially cylindrical core 9'2 is adapted to be slidably mounted between actuating sleeve 86 and dashpot sleeve Tl in a piston-like manner, and is normally maintained at the position shown on the drawing by a light coil compression spring 96, which reacts between the closed lower end of core 92 and collar 88 on actuating sleeve 86. The lower end of core 92 is provided with lateral vent openings 94, so that any iuid trapped within the core is free to escape during movement of the core.

The circuit through the interrupter thus far described extends from a terminal xture S8 secured by a bolt |00 to cover casting 20, by way of a exible conductor |02 to one terminal of solenoid coil 16, and then by a exible conductor |04 to a supporting plate |06 secured on contact rod 58, The circuit continues in the closed circuit position of the interrupter, to fixed contact 66 through spring 'l2 to terminal bolt 6 and terminal xture |4. It will be observed that solenoid coil 16 being connected in series in the circuit through the interrupter will be responsive to overloads above a predetermined value to exert suflicient force to attract solenoid core 92 upwardly. Upward movement of core 92 results rst in compressing light coiled spring 96 until the bottom of the core engages the lower end of actuating sleeve. at. whichis. then. raised into` engagement with shoulder 90 .on Contact` rod 58 to separatecontact head 64 from iixed contact 66. This causes an arc toform between the contacts and to cause further upward movement f contact rod 58 due to pressure built up within interruptor chamber 62, in a manner more particularly described in the previously mentioned Wallacepatent. Upward movement of contact rod 58 stresses spring 55 so that when the arc is finally extinguished and solenoid coil 'I8 is deenergized, spring 55 is free to move contact rod 58 downwardly to reclose the circuit.

Opening and closing Aof, the interrupter in the manner described above would continue indefinitely on continuing overloads, and to avoid this an integrating meansis provided, compris-` ing a tubular member |01 secured on the top leg of solenoid supporting frame 14, with a,

notched piston |09 therein adapted to be advanced each time the circuit opens by a generally U-shapedv pawl l l guided for sliding and tilting movement on a guide rod H also secured to the upper leg of frame 14. Pawl is normally held at a position where a portion thereof overlies iianged collar 88 on actuating sleeve 86, by a coiled compression spring H3 mounted on guide rod I5'. A check valve control inlet (not shown) is provided for the lower end of tubular member |51 so that when the interrupter operates t0 open the circuit and actuating sleeve 8B is moved upwardly, the iianged collar 88 tilts pawl IH into engagement with a notch of piston |99 and moves it upwardly a predetermined distance where it remains when the contacts reclose. There, is some leakage between piston |99- and tubular member |01 so that if the fault clears upon a iirst circuit reclosing operation, the piston |89 will slowly sink back to its original position. However, if the fault has not cleared upon the first reclosure of the interrupter, it will immediately reopen and this time pawl will engage a lower notch of piston |09 and raise it a further amount. If the fault is still present on the second reclosure of the interrupter, it will.

continue to open and close the circuit until piston' |09 has been advanced an amount suiiicient that the upper end thereof engages toggle lever 38 and moves this toggle lever upwardly overcenter so as to permit lockout spring 35 to rotate support '28 counterclockwise and hold contact rod 58 at an open circuit position. Such an operation will cause handle 44 to project beneath hood 24 to present a readily visible indication of the lockout condition of the interrupter.

In order to provide a time delay for a circuit opening and closing operations of the interrupter, use is made 0i the operation of core 92 in dashpot sleeve 11, and of the liquid displaced by movement of the core. For the purpose of delaying a circuit closing operation, contact rod 58 has a latch plate m8 pivotally mounted on supporting plate |06 of the rod, and latch plate |88 has a relatively large opening for receiving the .contact rod to permit pivotal movement thereof, it being normally biased upwardly by a coiled compression spring H. Latch plate |08 is also provided adjacent its pivot point with an aperture` for receiving a latch rod H2 iixedly mounted between cap 58 of the interrupter chamber and support plate 18. The lower end of latch rod H2 is reduced in section, and the aperture in the latch plate which receives rod H2 is of a size such that upon movement of contact rod 581.0 san. @een Circuit.. @Demoni latch-gelet?. 03 :Z5

may. pivot in .a clockwise. .direction while .com-.- pressing spring ||0 to relieve any tendency of the aperture therein to bind on latch rod H2. However, upon an attempted reclosing movement of contact rod 58, latch plate m8 will bind on rod |2 due to the action of spring HG, to thereby latch the contact rod in an open circuit position. This latch is adapted to be released by downward movement of solenoid core Q2, when the lower end thereof engages the outer end of latch plate |08, However, downward movement of core 92 is relatively slow due to its dashpot action in cooperation with sleeves 11 and 86, so that reclosing movement of contact rod 58 will be correspondingly slow until the reduced section at the lower end of latch rod H2 is reached, whereupon latch plate |53 can no longer bind on latch rod H2 and contact head G4 will rapidly move into nal engagement with nxeu contact 66.

The interrupter may be provided with certain accessories, such as a support H4 for a lightning arrester unit electrically connected between the cover casting and frame 14 by a. conductor H6, so that lightning surges will by-pass solenoid 15 and operation of the interruptor will be prevented. A counter H8 may also .be provided supported beneath hood 24 for actuation by a link |20 connected with an actuating lever |22 which is pivoted on shaft 28. Lever |22 may be movable with actuating lever 52 so as to register the number of operations of the interrupter on counter I3, which is visible from the exterior of the interrupter.

For the purpose of providing a time delay between the occurrence of an overload suflicient to attract core 52 upwardly and cause a circuit interrupting operation, and the time the contacts are actually separated, collar 15 and the upper leg of supporting frame 14 are provided with a passage |25 leading from the upper end of the dashpot space between sleeves 11 and S6 to a tubular chamber |24, which may be integrally formed with the top leg of support 14. Passage |25 is provided at the end thereof within tubular chamber |24 with a check valve disk |28 adapted to be seated thereon and permit c-w of iiuid solely in a direction into chamber |22. A piston |30 is freely slidably mounted in chamber |24, and the upper end of the chamber is provided with a cap |32 threadedly mounted thereon and having a substantially central aperture adapted to line up with the bore through a short tubular extension |34 threadedly associated with cap |32.

In operation, with casing 2 filled with an extinguishing fluid such as cil or the like, up to the level L, it will be observed that normally substantially no liquid will be present in chamber |24, so that when solenoid core 92 is attracted upwardly to interrupt the circuit, the liquid displaced thereby will be forced through passage |26 to unseat check valve |28 and move piston |30 upwardly a distance substantially into engagement with the lower end of tubular extension |34. When core 92 moves downwardly during a circuit closing operation check valve |25 will seat on the upper end of passage |26 to thus close the upper end of the dashpot space between sleeves 11 and S5, so that downward movement of core 92 will be relatively slow since liquid must be drawn into the dashpot space past the relatively small clearances between core 92 and sleeves 11 and |26.y If the interrupter remains closed after a iirst circuit interruption and re- ;closing operation, piston lvwillgraduallysinl;

back to its normal lower position due to the weight thereof, but this movement will also be quite slow due to the necessity of displacing liquid .below the piston past the relatively small clearance between piston |30 and chamber |24. However, if the fault has not cleared and the interrupter immediately reopens the circuit, piston |30 will be in engagement with the lower end of tubular extension |38 to thus block further upward movement of piston |30. This means that upward movement of core 92 will be much slower than on the first interruption due to the necessity of forcing liquid trapped in the dashpot space past the relatively small clearances between core 92 and sleeves TI and BE. Thus, with the structure disclosed, the interruptor will always operate on closely succeeding interrupting operations to separate the contacts at a relatively rapid rate on the first such interrupting operation, and at a slower rate on succeeding operations. However, if the fault clears before automatic lockout of the breaker occurs, piston |30 will reset so that the next time a continuing fault occurs, the same sequence of a first fast, and subsequent slower interrupting operations will occur.

The structure illustrated in Fig. l is also capable of providing other sequential arrangementsof fast and slow circuit interruptions on closely succeeding interrupting operations, for example by removing tubular extension |34, it will require two closely successive circuit opening operations to advance piston |30 into engagement with cap |32 to block further upward movement so that with extension |34 removed, a sequence of a first and second relatively rapid circuit interrupting operations will occur followed by subsequent time delayed circuit interrupting operations. Moreover, by removing piston |30 from chamber |24 all circuit interrupting operations will occur relatively rapidly since liquid may freely move out through passage |26. Similarly, all circuit interrupting operations of the interrupter may be caused to be delayed by the dashpot action of the solenoid core 92 by substituting for tubular extension |3 the extension |36 shown in Fig. 3, which is long enough when in place to engage and hold piston |35 at its lowermost position.

A modified arrangement for obtaining different circuit opening times is illustrated in Fig. 2, and since most of the parts illustrated therein are identical with those shown in Fig. l, like reference numerals are employed to designate such like parts. In this embodiment of the invention, the upper leg of supporting frame i4 is provided with a short tubular chamber |38 having interior threads for cooperation with a chamber extension |49 having exterior threads, so as to be threadedly mounted in chamber |38. The upper end of chamber extension H9 is closed except for a restricted vent opening |42, for a purpose to be described. Chamber extension |40 may be threaded into chamber |38 any desired amount, and be secured at an adjusted position by means of a lock nut |44.

The operation of the embodiment of the invention shown in Fig. 2 is similar to that shown in Fig. 1, in that on a first circuit interrupting operation liquid is forced from the dashpot space by upward movement of core 82, into chamber I 38 by displacement of check valve |28. This forcing of liquid into chamber |38 is substantially unopposed, because the air in the chamber may freely escape from vent |42. The adjustment of chamber extension |40 shown in Fig. 2 is substantially such that two closely successive circuit interrupting operations are required to entirely fill the chamber and extension |40 with liquid. This means that the first two circuit interrupting operations will occur substantially instantaneously, but if a third interrupting 0peration is attempted immediately after the second, it will be delayed, because chamber |38 and extension |40 being filled with liquid it will be necessary to force this liquid through restricted vent |42, and since the liquid has a much higher viscosity than air, the upward movement of core 92 will be correspondingly delayed. This, of course, will delay the third interrupting operation and any subsequent closely successive circuit interrupting operations. In the event the fault clears before automatic lockout of the interrupter occurs, liquid in chamber |38 may gradually leak back past check valve plate |28 until finally the chamber is again filled with air, so that if a continuing fault occurs at a later time the same sequence of closely successive circuit interrupting operations will occur, namely, a first and second relatively rapid interruption, and subsequent interruptions delayed by the dashpot action of core 92. The liquid level is preferably substantially coincident with plate |28.

It will be observed that in both embodiments of the invention check valve disk |28 operates to cause dashpot control of every circuit closing operation. The control for timing of circuit interrupting operations disclosed in the embodiment of the invention shown in Fig. 2 is capable of adjustment to obtain a different sequence of relatively rapid and slow interrupting operations similar to the adjustments obtainable with the embodiment of the invention shown in Fig. 1. Thus, by turning chamber extension |40 in a direction to telescope further into chamber |38. the chamber and extension may be made small enough so as to be lled with liquid during a. first circuit interrupting operation so that the second and closely succeeding interruptions will be delayed. If chamber extension 40 is threaded all the way into chamber |38 to engage check valve disk |28, it is apparent that all circuit interrupting operations will be delayed by the dashpot action of core 92, since check valve |28 will be held closed. Moreover, by entirely removing extension |48 from chamber |38, 'all circuit interrupting operations will occur substantially instantaneously.

From the foregoing, it is apparent that the invention disclosed herein provides in an automatic reclosing circuit interrupter, a single dashpot means for delaying all closing operations of the interrupter, and for delaying certain opening operations in any series of closely successive opening operations. Moreover, the control for timing the circuit opening operations may be adjusted to obtain a rst instantaneous and subsequent time delayed openings, or to provide for the first two circuit openings to be instantaneous in character with the subsequent openings time delayed, or to provide for all openings to be substantially instantaneous, or to be time delayed. y

Having described preferred embodiments of the invention, in accordance with the patent statutes, it is desired that this invention be not limited to these particular embodiments inasmuch as it will be readily apparent, especially to persons skilled in the art, that many modifications and changes may be made in these particular struc- 9 tures without departing from the broad spirit and scope of the invention.

4We claim as our invention:

1. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, said dashpot means having vent means associated therewith for the free passage of fluid displaced by operation of said dashpot means throughout a circuit interrupting operation, means preventing free flow of said displaced fluid in a reverse direction, and means actuated by the fluid displaced through said vent means during a predetermined circuit interrupting operation to close said vent means, whereby the next closely succeeding circuit interrunting operation will be delayed by said dashpot means.

2. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a circuit inter- .ruptingr operation, fluid dashpot means for delay- ,ing separation of said contacts after the occurrence of said predetermined condition, a chamber freely. communicating with said dashpot means bein- 2 of a site to relativen7 freely receive only a predetermined amount of fluid displaced .by operation of said dashpot means, which is greater than the amount of fluid displaced during a single operation, one-way valve means permitting free flow of displaced liquid into said chamber but preventing outflow, whereby said dashpot is substantially ineffective to delay separation of said contacts until a predetermined circuit interrupting operation when said predetermined amount of fluid has been displaced by said dashpot means.

3. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separating of said contacts, means for automatically7 reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, a. vented chamber freely communicating with said dashpot means so as to relatively freely receive iluid displaced by operation of said dashpot means, and means in said chamber responsive to the presence in said chamber cf a predetermined quantity oi said fluid which is greater than the amount of fluid displaced during a single operation for restricting said chamber vent, one-way valve means permitting free flow of displaced liquid into said chamber but preventing outflow, whereby said contacts are relatively quickly separated until said predetermined quantity of iluid has been displaced by said .dashpot means, whereupon the next circuit opening operation will be relatively slow.

4. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically, reclosing said contacts following a circuit .interrupting operation, fluid dashpot means for Adelaying separation of said contacts after the oc- Icurrence. of V,said predetermined condition, a

vented'chamber freely communicating with said da'shpot means so as to relatively freely receive fluid displaced by operation of said dashpot means, one-way valve means permitting free flow of displaced liquid into said chamber but preventing outflow, said chamber normally containing a less viscous fluid than that employed by said dashpot means, the vent for said chamber being of a size to impede the flow of dashpot fluid therefrom but affording substantially no resistance to the escape of said less Viscous fluid, s0 that said contacts are relatively quickly separated until said chamber is filled with said displaced liquid, after which they are relatively slowly separated.

5. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing leparation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, a chamber freely communicating with said dashp'ot means so as to relatively freely receive only a predetermined amount of fluid displaced by operation of said dashpot means which is greater than the amount of iluid displaced during a single operation, means whereby said displaced ,fluid may relatively slowly leak out of said chamber so that said dashpot means is substantially ineffeet-ive to delay widely separated circuit interrupting operations of said interrupter but is operative to delay a predetermined circuit interrupting operation in any series of closely successive circuit interrupting operations when said dashpot means has filled said chamber with said predetermined amount of fluid.

6. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation of said contacts afterthe occurrence of said predetermined condition, a vented chamber freely communicating with said dashpot means so as to relatively freely receive fluid displaced by operation of said dashpot means, means whereby said displaced fluid may relatively slowly leali out of said chamber, and in said chamber resnonsive to the presence in said chamber of a predetermined quantity of said fluid which is greater than the amount of fluid displaced during a single operation for restricting said chamber vent, so that said dashpot means is substantially ineffective to delay widely separated circuit interrupting operations of said interrupter but is operative to delay a predetermined circuit interrupting operation in any series of closely successive circuit interrupting operations when said dashpot means has filled said chamber with said predetermined amount of fluid.

7. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, a chamber having a restricted vent, said Vented chamber freely communicating with saidV dashpot means so as to relatively freely receive 'only a predetermined quantity of fluid displaced by operation of said dash pot means which is greater than the amount of fluid displaced during a single operation, said chamber normally containing a less viscous fluid than that employed by said dashpot means, the vent for said chamber being of a size to impede the flow of dashpot fluid therefrom but affording substantially no resistance to the escape of said less viscous fluid, means whereby said displaced fluid may relatively slowly leak out of said chamber, so that said dashpot means is substantially ineffective to delay widely separated circuit interrupting operations of said interrupter but is operative to delay a predetermined circuit interrupting operation in any series of closely successive circuit interrupting operations when said dashpot means has filled said chamber with said predetermined amount of fluid.

8. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition. said dashpot means having vent means associated therewith for the free passage of fluid displaced by operation of said dashpot means, means preventing free flow of said displaced fluid in a reverse direction, and means responsive to an amount of fluid displaced by said dashpot through said vent means in a predetermined time which is greater than the amount of fluid displaced during a single operation for closing said vent means so that at least one predetermined circuit interrupting operation in any series of relatively closely successive circuit interrupting operations will be delayed by said dashpot means.

9. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causingr separation of said contacts, means for automatically reclosing said contacts following circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, said dashpot means having vent means associated therewith for the passage therethrough of fluid displaced by operation of said dashpot means, means preventing free flow of said displaced fluid in a reverse direction, means responsive to the r amount of fluid displaced by said dashpot means through said vent means in a predetermined time which is greater than the amount of fluid displaced during a single operation for restricting said vent means so that at least one predetermined circuit interrupting operation in any series of relatively closely successive circuit interrupting operations will be delayed lby said dashpot means,

and said last-mentioned means having a manually adjustable part for determining the number of circuit interrupting operations in any such series of closely successive operations which are delayed by said dashpot means.

10. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a cir-"V cuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, a chamber freely communicating with said dashpot means so as to relatively freely receive only a l predetermined amount of fluid displaced by operation of said dashpot means. which is greater than the amount of fluid displaced during a single operation, means whereby said displaced fluid may relatively slowly leak out of said chamber so tha-t said dashpot means is substantially ineffective to delay widely separated circuit interrupting operations of said interrupter but is operative to delay a .predetermined circuit interrupting operation in any series of closely successive circuit interrupting operations when said dashpot means has filled said chamber with said predetermined amount of fluid, and means whereby said predetermined amount of fluid may be varied for determining said predetermined circuit interrupting operation.

11. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condi-tion, a vented chamber communicating with said dashpot means so as to relatively freely lreceive fluid displaced by operation of said dashpot means during a circuit interrupting operation, means whereby said displaced fluid may relatively slowly leak out of said chamber, means in said chamber responsive to the presence in said chamber of a predetermined quantity of said fluid which is greater than the amount of fluid displaced duringa single operation for restricting said chamber vent, so that said dashpot means is substantially ineffective to delay widely separated circuit interrupting operations of said interrupter but is operative to delay a predetermined circuit interrupting operation in any series of closely successive circuit interrupting operations when said dashpot means has filled said chamber withsaid predetermined amount of fluid, and said quantity responsive means being adjustable to thereby determine said predetermined circuit interrupting operation.

12. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, a vented chamber communicating with said dashpot means so as to relatively freely receive fluid displaced by operation of said dashpot means, said chamber normally containing a less viscous fluid than that employed by said dashpot means, the vent for said chamber being of a size to impede the flow of dashpot fluid therefrom but affording substantially no resistance to the escape of said less viscous fluid, means whereby said displaced fluid may relatively slowly leak out of said chamber so that said dashpot means is substantially ineffective to delay widely separated circuit interrupting operations of said interrupteq` but is operative to delay a predetermined circuit interrupting operation in any series of closely successive circuit interrupting operations when said dashpot means has filled said chamber with said predetermined amount of fluid, and said chamber being adjustable in size to thereby determine said predetermined circuit interrupting operation.

13. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for I3 Aautomatically reclosing -said contacts following 'circuit' -interrupting operation, fluid dashpot means for delaying separation ofV said contacts "after the occurrence of said predetermined ccnrdition, said dashpot' means having-vent means associated therewith which is'open duringa circuit-interruption operation for the passage'therethroughof liuid displaced by" operation of said dashpot means, means preventing free flow of said displaced fluid in aireverse direction, means responsive to an amount-of fluid-displaced bysaid dashpot in a lpredetermined time' which is greater than :the'amount Voffluid displaced duringV a singlefop'eration -for restricting` said -vent means T-so'that atf-le'ast' one: predetermined circuit interl rupting operation in =any= series of relatively -closely successive circuit-interrupting ioperations "will'befdelayed'by said dashpot-means,-and man- -ually adjustable .'means Vcrrendering-:saidY -iluid A .responsive-means inoperative, "whereby all cirvcuitcpening operations of -said interrupter may f occur relatively rapidly.

-14.-.-Inan automatic .reclosing circuit interrupter -havingseparable contacts, Vmeans responsive to a predetermined circuit-condition for causing-separation of said contacts, means for automatically f yreclosing-said contacts following a 'circuit interrupting Aoperation, fluid 'dashpot Ymeans for delaying separation oisaid contacts after A*the 'occurrence of saidv predetermined-condition, Isaid dashpot means -having vent "means Vassociated therewith-which is openduringa circuit interruption operation -for vthe fpassage therethrough -of -uid 'displaced by 'operation of said dashpot -means,Vv 'means-preventing free Aflow of said disrplaced iiuidy in Ia-reverse direction, means re- 'Y sponsive toan amount of `fluid-displaced by said i.dashpot in r-a Hpredetermined time -which is greater than the amountof uid displaced during --.a.singlefoperation-for closing -said'verrt means so that at least one predetermined circuit interrupting-:operation `inlany series of relativelyvclosely succ'essiveicircuitinterrupting operations will be delayed: by said' dashpotmeans iand manually *adiustable Vmeans for closing said vent-means-so that-fall circuit interrupting operations `of said nterrupter can be delayed by said dashpot means. 15. In an automatic reclosing circuit interrupter 'having separable contacts, means-responsive to `apredetermined circuit condition for 'causing separation of said contacts, means for automatically. reclosing said contacts followingcircuit yinterrupting operation, uid dashpot means for delaying Vseparation ofsaid contacts after the occurrence of said predetermined condition, said A`sive circuit interrupting operations will-be del' layed'byvsaid dashpot means, Aand manually ad- .'justable means for selectively rendering' saidfluid responsive'means inoperative 'or for closing said vent means.' so thatall' circuit vopi'ening 'operations lmay occur relatively rapidly,'cr'all may be'delay'ed by said dashpot means.

16. In an automatic reclosing circuit intercausing separation of said contacts, means` for automatically reclosing said contacts'following a circuit interrupting ope-ration, uid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, said dashpot means having vent means associated therewith which is open during acircuit interruption operation for the passage therethrough of duid displaced by operation of said dashpot means, valve means responsive to a circuit interrupting operation of said -interrupter to open said vent means and being responsive to a circuit closing operation of saidinterrupter to substantially close said Ventmeans, whereby at least circuit closingv operations of said interrupterf-are delayed by said dashpot means, means responsive to one-predetermined circuit opening operation of -said interrupter to restrict said vent means, said operation responsive means being biased to slowly return to its normalposil tionwhere -it is inoperative to restrict said vent means, whereby only'a circuit opening operation closely succeeding said one operation will be delayed by said dashpot means, and said operation responsive means having a manually adjustable part for preventing operation of said voperation responsive means so that no-circuit interrupting operations of said interrupter will be delayed by said dashpot means.

17. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation ofsaid contacts after the occurrence of said predetermined'condition, said dashpot means-having vent means associated therewith which is open during a circuit interruption operation for the passage therethrough of fluid displaced by operation of said dashpot means, valve means responsive to a circuit interrupting operation of said interrupter to open said vent means and being responsive to a circuit closing operation ci said interrupter to substantially close said vent means, whereby at least circuit closing operations of said interrupter are delayed by said dashpot means, means responsive to one predetermined circuit opening operation ci said interrupter to restrict said vent means, said operation responsive means being sbiased to slowly return to its normal position Where it is inoeprative to restrict said vent means, whereby only a circuit opening operation closely succeeding said one operation will be delayed by said dashpot means, and said operation responsive means having a manually adjustable part for closing said vent means at all times so that a-ll opening and closing ope-rations of said interrupter will be delayed by said dashpot means.

18. In an automatic reclosing circuit -interrupter having separable contacts, means responsive to a lpredetermined circuit condition for causing separation of said contacts, meansA for automatically reclosing said contacts following a circuit interrupting operation, uid dashpot means for delaying separation of said contacts after the occur-rence of said predetermined condition, said dashpot means having vent means associated therewith which is open during a circuit interruption operation for the passage rthere'- through -of fluid displacedby operation 'of' vsaid dashpot means, valve means responsive to a circuit interrupting operation of said interrupter to open said vent means and Ibeing responsive to a circuit closing operation of said interrupter to substantially close said vent means, whereby at least circuit closing operati-ons of said interrupter are delayed by said dashpot means, means responsive to one predetermined circuit opening operation of said interrupter to close said vent means, said operation responsive means being biased to slowly return to its normal position where it is inoperative to close said vent, whereby only a circuit opening operation closely succeeding said one operation will be delayed by said dashpot means, and said operation responsive means having a manually adjustable part for closing said vent means at all times or for preventing operation of said operation responsive means, so that all opening and closing operations of said interrupter will be delayed by saiddashpot means, or for preventing the delay of any circuit interrupting operation by said dashpot means.

19. In an automatic reclosing circuit interrupter having separable contacts, means responsive to a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, said dashpot means having vent'means associated therewith for the passage therethrough of fluid displaced :by operation of said dashpot means during a circuit interrupting operation, means preventing free flow of said displaced fluid in a reverse direction, means responsive to one predetermined circuit opening operation of said interrupter to restrict said vent means so that the succeeding circuit interrupting operation will be delayed by said dashpot means, said operation responsive means being biased to slowly return to its normal position where it is inoperative to restrict said ven-t means, whereby only a circuit opening operation closely succeeding said one operation will be delayed by said dashpot means, said operation responsive means having a manually adjustable part, means for preventing operation of said operation responsive means'so that no circuit interrupting operations of said interrupter will be delayed by said dashpot means.

20. In an automatic reclosing circuit interrup ter having separable contacts, means responsive to a predetermined circuit condition for causing .separation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, iluid dashpot means for delaying separation of said contacts after the occurrence of said -predetermined condition, said dashpot means having vent means associated therewith for the passage therethrough of fluid displaced by operation of said dashpot means during a circuit interrupting operation, means responsive to one predetermined circuit opening operation of said interrupter to restrict said vent means so that the successive circuit interrupting operation will be delayed :by said dashpot means, a part of said operation responsive means being biased to slowly return to its normal position where it is inoperative to close said vent, whereby only a circuit opening operation closely succeeding said one operation will be delayed by said dashpot means, and manually adjustable means for closing said vent means at all times 4so that all opening and closing operations of said interrupter will be delayed by said dashpot means.

21. In an automatic reclosing circuit interrupter having separable contacts, means responsive to. a predetermined circuit condition for causing separation of said contacts, means for automatically reclosing said contacts following a circuit interrupting operation, fluid dashpot means for delaying separation of said contacts after the occurrence of said predetermined condition, said dashpot means having vent means associated therewith for the passage therethrough of fluid displaced by operation of said dashpot means during a circuit interrupting operation, means responsive to one predetermined circuit opening operation of said interrupter 'to restrict said vent means so that the succeeding circuit interrupting operation will be delayed .by said dashpot means, a part of said operation responsive means being biased to slowly return to its normal position where it is inoperative to close said vent, whereby only a circuit opening operation closely succeeding said one operation will be delayed by said dashpot means, and manually adjustable means for closing said vent means at all times or for preventing operation of said operation responsive means so that all opening and closing operations of said interrupter will be delayed by said dashpot means, or for preventing the delay of any circuit interrupting operation by said dashpot means.

22. An automatic reclosing circuit breaker compri-sing, separable contacts, means responsive to an overload on the circuit for automatically separating said contacts to open the circuit, means responsive to a circuit-opening operation for automatically closing said contacts, means responsive to a predetermined number of closely successive circuit opening operations for maintaining said contacts separated, fluid pumping means actuated by said contact separating means for supplying fluid to a counter cylinder, a counting piston in said cylinder biased to anormal position from which it is advanced a predetermined amount by the fluid supplied by said pumping means on each circuit-opening operation of the breaker, and a mechanical stop positioned to be engaged by said piston when advanced a farther amount by a number of closely succeeding circuit-opening operations of said breaker which is less than said predetermined number to prevent further movement of said piston, whereby the next closely succeeding circuit-opening operation will be delayed by the thus imposed resistance to fluid ilow from said pumping means to said counting cylinder.

HERBERT L. RAWLINS. JAMES M. WALLACE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Van Ryan et al July 17, 1951 

